The more I study biological psychology and how the senses work, the more I am amazed that we ever gain agreement on anything at all (a slight exaggeration there, but hopefully you see my point).

In another thread I posted a moving GIF that - when looked at in a certain way - the brain would alter the way it perceived a colour, despite the colour not actually changing. That about sums up the brain for me, and how we perceive things - how easily we can "see" something that did not actually exist. Never mind "hallucinating", its perfectly possible just to "see" something that simply is not what is actually there.

As for exaggerating and lying....I've several times been in a situation listening to someone tell a story of something I witnessed, and thinking "but....that didn't happen like that!". Clearly ONE of us is wrong - at least to the extent of how we imparted emotionaly reactions to the event - and neither deliberately lying, so what does that mean?

To me - in those occasions - it means that if the ONLY version of the story trasmitted had been the other person's, then the story remembered in the future would be the one that I believe was incorrect. And, if I had told the tale, then the story going forward for posterity would be wrong from their point of view. And in neither case would either tale have necessarily been correct.

Which all means that "I saw or experienced this" is a very shaky ground for the truth of the matter. 99.999% of the time, it doesn't matter, of course. If I tell you how I saw a blackbird eat from my birdtable, it matter not the slightest that it was a crow, or a seagull. But sometimes it DOES matter - and those are the tales that we need to be able to examine carefully.